Correct errors in the downloaded browscap file

When I contacted Gary Keith regarding this issue, he replied as follows:

Hi Bob,

Thanks for contacting me. This is an issue I've been aware of for some time
now. Several people have filed bug reports about this issue, only to be
rudely dismissed by the person who maintains the get_browser code for PHP.
His reply was always along the lines of, this is by design therefore it's
not a bug. And yet, there doesn't seem to be any workout I can implement
within the browscap.ini file itself, because the characters you mentioned
can't be removed. The semicolon, for example, is a required token separator.
My suggestion has always been to start using the PHP class Jonathan Stoppani
wrote that's available for download on my site. It's supposed to be far more
efficient than get_browser, and it can use the native browscap.ini file.
Perhaps you can get your code included in the core code for the get_browser
function. Eventually I will have to deprecate both php_browscap.ini and
lite_php_browscap.ini.

Regards,
~gary.

A simple workaround is to simply backslash-escape the offending characters.

Upgrading to critical because without this change, the whole module is basically useless.